JP2016044254A - Polyester elastomer resin composition for blow molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve problems such as instability of melt viscosity due to residence, wall thickness unevenness of a blow molded article caused by the instability, inner face failure of the blow molded article by melt fracture and production of gelatinization article, in a thickening resin composition.SOLUTION: There is provided a polyester elastomer resin composition for blow molding containing 100 pts.mass of (A) a thermoplastic polyester elastomer obtained by bonding a hard segment consisting of polyester having aromatic dicarboxylic acid and an aliphatic and/or alicyclic glycol as a constituent to at least one kind of soft segment selected from aliphatic polyether, aliphatic polyester and aliphatic polycarbonate, 0.5 to 5 pts.mass of (B) a glycidyl group-containing styrenic polymer, 0.1 to 5 pts.mass of (C) organic carboxylic acid alkali metal salt having 3 to 40 carbon atoms and 0 to 3 pts.mass of (D) an inorganic crystal nucleus agent and having cooling crystallization temperature (TC2) of 170°C or higher and D hardness of 35 or more.SELECTED DRAWING: None

Description

  The present invention relates to a polyester elastomer resin composition for blow molding. More specifically, the present invention relates to a polyester elastomer resin composition for blow molding that is excellent not only in melt viscosity stability and blow moldability but also in bending fatigue under a high temperature environment.

  Thermoplastic polyester elastomer is excellent in injection moldability and extrusion moldability, has high mechanical strength, elastic properties, rubber properties such as impact resistance, flexibility, and cold resistance. It is used for applications such as electronic parts, fibers and films.

In order to further expand applications, various modifications and alloys have been attempted to enhance the properties of thermoplastic polyester elastomers and add further properties.
For example, Patent Document 1 proposes blending an ionomer resin and a maleic anhydride-modified aromatic vinyl copolymer in order to improve toughness.
Patent Document 2 proposes that an alkali metal salt of an organic carboxylic acid having 3 to 40 carbon atoms and a polyfunctional glycidyl group-containing styrenic polymer are blended in order to develop transparency in the molded product.
On the other hand, thermoplastic polyester elastomers were unsuitable for blow molding because of their low melt viscosity, but methods of increasing the viscosity with polyepoxy compounds and polyisocyanate compounds have come to be adopted, and are also applicable to blow molded products. It has been adopted taking advantage of the characteristics of thermoplastic polyester elastomer (Patent Documents 3, 4, etc.).

  However, when thickening with polyepoxy compounds or polyisocyanate compounds, the melt viscosity is not stable due to residence during molding, which may be affected by residence time, resulting in gelation or decomposition products. In some cases, unevenness in thickness at the time of blow molding occurs, or the inner surface of the blow molded product may be roughened by melt fracture, and improvement has been desired.

  By the way, in Patent Document 2, although good transparency is exhibited in a low-hardness thermoplastic polyester elastomer, transparency may be poor in a high-hardness thermoplastic polyester elastomer. In Patent Document 2, there is no suggestion about application in the field of opaque molded products such as blow molded products, which are thermoplastic polyester elastomers with high hardness.

Japanese Patent Laid-Open No. 2001-234042 International Publication No. 2013/157593 Japanese Patent No. 2787773 Japanese Patent No. 3714747

  An object of the present invention is to provide a thickened resin composition containing a reactive material having a plurality of glycidyl groups, instability of melt viscosity due to retention during molding, uneven thickness of a blow molded product, melt fracture It is an object of the present invention to provide a thermoplastic polyester elastomer composition excellent in moldability that can improve problems such as poor inner surface of blow-molded products and generation of gelled products.

The present inventor has reached the present invention by finding that the combination of the alkali metal organic carboxylic acid salt and the glycidyl group-containing styrenic polymer contributes to improvement of moldability and increase of melt viscosity with a small amount of compounding. .
That is, the present invention is as follows.

[1] A hard segment composed of a polyester composed of an aromatic dicarboxylic acid and an aliphatic and / or alicyclic glycol, and at least one kind of software selected from an aliphatic polyether, an aliphatic polyester, and an aliphatic polycarbonate 0.5 to 5 parts by mass of a glycidyl group-containing styrene polymer (B) and 3 to 40 carbon atoms of an organic carboxylic acid alkali metal salt (100 parts by mass of a thermoplastic polyester elastomer (A) formed by bonding segments ( C) 0.1 to 5 parts by mass and (D) 0 to 3 parts by mass of an inorganic crystal nucleating agent, and the temperature-falling crystallization temperature (TC2) is 170 ° C. or higher and D hardness 35 or higher. A polyester elastomer resin composition for blow molding.
[2] The thermoplastic polyester elastomer (A) is a copolymer mainly comprising terephthalic acid, 1,4-butanediol and polyoxytetramethylene glycol, and the number average molecular weight of the polyoxytetramethylene glycol Is a polyester elastomer resin composition for blow molding as described in [1], wherein the copolymerization amount is 5 to 20 mol% with respect to all glycol components constituting the thermoplastic polyester elastomer (A).
[3] The glycidyl group-containing styrene polymer (B) is a glycidyl group-containing styrene acrylic polymer, and has a weight average molecular weight (Mw) of 1000 or more and an epoxy value of 0.5 meq / g or more [1] or The polyester elastomer resin composition for blow molding as described in [2].
[4] The organic carboxylic acid of the alkali metal salt having 3 to 40 carbon atoms (C) is an aliphatic carboxylic acid having 3 to 20 carbon atoms, according to any one of [1] to [3]. Polyester elastomer resin composition for blow molding.
[5] The polyester elastomer resin composition for blow molding according to any one of [1] to [4], wherein the inorganic crystal nucleating agent (D) is talc.
[6] For blow molding according to any one of [1] to [5], wherein the polyester elastomer resin composition has a melt flow rate of 230 ° C. and a load of 2.16 kg of 0.1 to 3.0 g / 10 min. Polyester elastomer resin composition.
[7] The polyester elastomer resin composition for blow molding according to any one of [1] to [6], wherein the polyester elastomer resin composition has a number of breaks of 120 ° C. dematcher of 3 million times or more.
[8] The thermoplastic polyester elastomer (A) is blended with a glycidyl group-containing styrenic polymer (B) as a thickener, and an organic metal carboxylic acid alkali metal salt having 3 to 40 carbon atoms as a crystal nucleating agent and a reaction catalyst ( A process for producing a polyester elastomer resin composition for blow molding, which comprises blending C).

  Although it has a high melt viscosity, it is possible to suppress a decrease in the crystallization speed, so that it is excellent in moldability during blow molding. That is, problems such as uneven thickness of the blow-molded product, inner surface defects of the blow-molded product due to melt fracture, and generation of gelled products can be improved. Further, the obtained molded article is excellent in bending fatigue resistance.

[Thermoplastic polyester elastomer (A)]
The thermoplastic polyester elastomer (A) used in the present invention comprises a hard segment comprising a polyester comprising an aromatic dicarboxylic acid and an aliphatic and / or alicyclic glycol as constituent components, an aliphatic polyether, an aliphatic polyester, and A thermoplastic polyester elastomer in which at least one soft segment selected from aliphatic polycarbonates is bonded.

  In the thermoplastic polyester elastomer (A) used in the present invention, as the aromatic dicarboxylic acid constituting the hard segment polyester, ordinary aromatic dicarboxylic acids are widely used and are not particularly limited, but as the main aromatic dicarboxylic acids, Desirable is terephthalic acid or naphthalenedicarboxylic acid. Naphthalenedicarboxylic acid is preferably 2,6-naphthalenedicarboxylic acid among the existing isomeric structures. Other acid components include diphenyl dicarboxylic acid, isophthalic acid, aromatic dicarboxylic acid such as 5-sodium sulfoisophthalic acid, cycloaliphatic dicarboxylic acid, alicyclic dicarboxylic acid such as tetrahydrophthalic anhydride, succinic acid, glutaric acid, adipine Examples thereof include aliphatic dicarboxylic acids such as acid, azelaic acid, sebacic acid, dodecanedioic acid, dimer acid, and hydrogenated dimer acid. These are used within a range that does not significantly lower the melting point of the thermoplastic polyester elastomer, and the amount thereof is preferably less than 30 mol%, more preferably less than 20 mol% of the total acid component.

  Further, in the thermoplastic polyester elastomer (A) used in the present invention, the aliphatic or alicyclic glycol constituting the hard segment polyester is widely used as a general aliphatic or alicyclic glycol, and is not particularly limited. The alkylene glycols mainly having 2 to 8 carbon atoms are desirable. Specific examples include ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol and the like. Of these, ethylene glycol or 1,4-butanediol is preferable for imparting heat resistance.

  The component constituting the hard segment polyester is preferably a butylene terephthalate unit or a butylene naphthalate unit from the viewpoint of physical properties, moldability, and cost performance.

  Moreover, the aromatic polyester suitable as polyester which comprises the hard segment in the thermoplastic polyester elastomer (A) used by this invention can be easily obtained according to the manufacturing method of a normal polyester. Moreover, what has the number average molecular weight 10000-40000 is desirable for this polyester.

The soft segment of the thermoplastic polyester elastomer (A) used in the present invention is at least one selected from aliphatic polyether, aliphatic polyester, and aliphatic polycarbonate. Aliphatic polyethers include polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, polyoxyhexamethylene glycol, polyoxytrimethylene glycol, copolymers of ethylene oxide and propylene oxide, ethylene oxide of polyoxyethylene glycol Examples include adducts, copolymers of ethylene oxide and tetrahydrofuran, and the like.
Examples of the aliphatic polyester include poly (ε-caprolactone), polyenantlactone, polycaprylolactone, and polybutylene adipate.

  The aliphatic polycarbonate is preferably composed mainly of an aliphatic diol residue having 2 to 12 carbon atoms. Examples of these aliphatic diols include ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 2, 2-dimethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,9-nonanediol, 2-methyl-1,8- Examples include octanediol. In particular, an aliphatic diol having 5 to 12 carbon atoms is preferable from the viewpoint of flexibility and low temperature characteristics of the obtained thermoplastic polyester elastomer (A). These components may be used alone or in combination of two or more as required, based on the case described below.

  In the present invention, the aliphatic polycarbonate diol having a low temperature characteristic and constituting the soft segment of the usable thermoplastic polyester elastomer preferably has a low melting point (for example, 70 ° C. or less) and a low glass transition temperature. . In general, an aliphatic polycarbonate diol composed of 1,6-hexanediol used to form a soft polyester elastomer soft segment has a low glass transition temperature of around -60 ° C and a melting point of around 50 ° C. Good low temperature characteristics. In addition, an aliphatic polycarbonate diol obtained by copolymerizing an appropriate amount of, for example, 3-methyl-1,5-pentanediol with the above aliphatic polycarbonate diol has a glass transition point with respect to the original aliphatic polycarbonate diol. Although the melting point is slightly increased, the melting point is lowered or becomes amorphous, so that it corresponds to an aliphatic polycarbonate diol having good low-temperature characteristics. In addition, for example, an aliphatic polycarbonate diol composed of 1,9-nonanediol and 2-methyl-1,8-octanediol has a melting point of about 30 ° C. and a glass transition temperature of about −70 ° C., which is sufficiently low. Corresponds to a good aliphatic polycarbonate diol.

  The thermoplastic polyester elastomer (A) used in the present invention is a copolymer mainly composed of terephthalic acid, 1,4-butanediol, and polyoxytetramethylene glycol for reasons of economy, heat resistance, and cold resistance. Preferably there is. In the dicarboxylic acid component constituting the thermoplastic polyester elastomer (A), terephthalic acid is preferably 40 mol% or more, more preferably 70 mol% or more, further preferably 80 mol% or more, It is particularly preferably 90 mol% or more. In the glycol component constituting the thermoplastic polyester elastomer (A), the total of 1,4-butanediol and polyoxytetramethylene glycol is preferably 40 mol% or more, more preferably 70 mol% or more, More preferably, it is 80 mol% or more, and it is especially preferable that it is 90 mol% or more.

  The number average molecular weight of the polyoxytetramethylene glycol is preferably 500 to 4000. If the number average molecular weight is less than 500, it may be difficult to develop the elastomer characteristics. On the other hand, when the number average molecular weight exceeds 4000, the compatibility with the polyester portion constituting the hard segment of the thermoplastic polyester elastomer (A) is lowered, and it may be difficult to copolymerize in a block form. The number average molecular weight of polyoxytetramethylene glycol is more preferably 800 or more and 3000 or less, and further preferably 1000 or more and 2500 or less.

  The copolymerization amount of the polyoxytetramethylene glycol is preferably 5 to 20 mol% with respect to all glycol components constituting the thermoplastic polyester elastomer (A). The polyoxytetramethylene glycol is more preferably 7 mol% or more and 18 mol% or less, and further preferably 8 mol% or more and 15 mol% or less with respect to the total glycol component.

  In the thermoplastic polyester elastomer used in the present invention, the mass part ratio of crystalline polyester constituting the hard segment and at least one selected from aliphatic polyether, aliphatic polyester and aliphatic polycarbonate constituting the soft segment is: Preferably, hard segment: soft segment = 30: 70 to 95: 5, more preferably 40:60 to 90:10, still more preferably 45:55 to 87:13, and particularly preferably 50:50 to 85: A range of 15.

  The thermoplastic polyester elastomer (A) used in the present invention is preferably a crystalline polyester having a melting point of 150 ° C. or higher and 230 ° C. or lower so that it can be distributed at room temperature. The melting point of the thermoplastic polyester elastomer (A) is more preferably 180 to 220 ° C. If the melting point is lower than 150 ° C, it is difficult to satisfy heat resistance characteristics for automobiles and home appliances. If the melting point exceeds 230 ° C, crystallinity as a polyester elastomer is high, and sufficient bending fatigue properties may not be obtained. .

  The reduced viscosity of the thermoplastic polyester elastomer (A) used in the present invention is preferably 0.50 dl / g or more and 3.50 dl / g or less when measured by the measurement method described later. If it is less than 0.50 dl / g, the durability as a resin is low, and if it exceeds 3.50 dl / g, workability such as injection molding may be insufficient. The reduced viscosity of the thermoplastic polyester elastomer (A) is more preferably from 1.00 dl / g to 3.00 dl / g, and even more preferably from 1.50 dl / g to 2.80 dl / g. The acid value is preferably 200 eq / t or less. Since the glycidyl group-containing styrenic polymer (B) described later is contained in the resin composition, 50 eq / t or less is particularly preferable in order to avoid gelation during mixing.

  The thermoplastic polyester elastomer (A) used in the present invention preferably has a surface hardness of 35 or more in terms of D hardness (JIS K7215), more preferably 38 or more, and still more preferably 40 or more. When the D hardness is less than 35, the effect of improving the moldability of the composition using the thermoplastic polyester elastomer (A) is small, and the effect of improving the bending fatigue property of the molded product may be low. The upper limit of the surface hardness is not particularly limited, but is about 60 due to the characteristics of the thermoplastic polyester elastomer.

  The thermoplastic polyester elastomer (A) used in the present invention can be produced by a known method. For example, a method of transesterifying a lower alcohol diester of a dicarboxylic acid, an excess amount of a low molecular weight glycol, and a soft segment component in the presence of a catalyst and polycondensing the resulting reaction product, or a dicarboxylic acid and an excess amount of glycol and A method in which a soft segment component is esterified in the presence of a catalyst and the resulting reaction product is polycondensed. In addition, a hard segment is prepared in advance, and a soft segment component is added thereto and randomized by a transesterification reaction. The method, the method of connecting the hard segment and the soft segment with a chain linking agent, and when poly (ε-caprolactone) is used for the soft segment, any method such as addition reaction of ε-caprolactone monomer to the hard segment may be used.

[Glycidyl group-containing styrene polymer (B)]
The glycidyl group-containing styrenic polymer (B) used in the present invention is a copolymer containing a glycidyl group-containing unsaturated monomer and a vinyl aromatic monomer as monomer components, and a thermoplastic polyester elastomer (A) and Those having good compatibility are preferred. The glycidyl group-containing styrenic polymer (B) preferably has a weight average molecular weight (Mw) of 1000 or more, an epoxy value of 0.5 meq / g or more, a weight average molecular weight (Mw) of 1000 to 50000, and an epoxy value of 0.00. The thing of 5-3 meq / g is more preferable.

The glycidyl group-containing styrene polymer (B) is preferably a copolymer of a glycidyl group-containing unsaturated monomer and a vinyl aromatic monomer.
Examples of glycidyl group-containing unsaturated monomers include unsaturated carboxylic acid glycidyl esters and unsaturated glycidyl ethers, and examples of unsaturated carboxylic acid glycidyl esters include glycidyl acrylate, glycidyl methacrylate, and monoglycidyl itaconate. Among them, glycidyl methacrylate is preferable.
Examples of the unsaturated glycidyl ether include vinyl glycidyl ether, allyl glycidyl ether, 2-methylallyl glycidyl ether, and methacryl glycidyl ether, with methacryl glycidyl ether being preferred.
Examples of the vinyl aromatic monomer include styrene monomers such as styrene, methylstyrene, dimethylstyrene, and ethylstyrene, and styrene is preferable.

  As long as the compatibility with the thermoplastic polyester elastomer (A) is not impaired, acrylic acid or methacrylic acid alkyl ester having 1 to 7 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl ester of (meth) acrylic acid, etc. (Meth) acrylic acid ester monomers, (meth) acrylonitrile monomers, vinyl ester monomers such as vinyl acetate and vinyl propylate, (meth) acrylamide monomers, maleic anhydride, maleic acid mono Monomers such as esters and diesters may be copolymerized. However, since α-olefins such as ethylene, propylene, and butene-1 tend to lose compatibility with the polyetherester block copolymer (A), those that are not copolymerized are preferred.

The glycidyl group-containing styrene polymer (B) is a glycidyl group-containing styrene acrylic polymer, and preferably has a weight average molecular weight (Mw) of 1000 or more and an epoxy value of 0.5 meq / g or more.
At this time, the weight average molecular weight (Mw) is more preferably 5000 or more, further preferably 8000 or more, and particularly preferably 9000 or more. When the weight average molecular weight (Mw) is less than 1000, glycidyl groups per molecule are decreased, and the thickening effect may be lowered. The weight average molecular weight (Mw) is preferably 50000 or less, more preferably 20000 or less, and further preferably 15000 or less, for reasons of compatibility with the thermoplastic polyester elastomer (A). The epoxy value is more preferably 0.6 meq / g or more, and further preferably 1 meq / g or more. If the epoxy value is less than 0.5 meq / g, the thickening effect may be lowered. The epoxy value is preferably 3 meq / g or less from the reason of suppressing the generation of gelled product due to excessive reaction with the thermoplastic polyester elastomer (A).
In order to satisfy such an epoxy value, the copolymerization ratio of the glycidyl group-containing unsaturated monomer and the vinyl aromatic monomer is preferably the copolymerization amount of the glycidyl group-containing unsaturated monomer. Is 1-30 mass%, More preferably, it is 2-20 mass%. If the copolymerization amount of the glycidyl group-containing unsaturated monomer is less than 1% by mass, the effect of thickening is small and sufficient bending fatigue properties tend not to be obtained, and if it exceeds 30% by mass, the stability as a resin composition is obtained. May be damaged.

  The blending ratio (content ratio) of the thermoplastic polyester elastomer (A) and the glycidyl group-containing styrene polymer (B) in the resin composition of the present invention is (A) / (B) = 100 / 0.5 to mass ratio. 5. If the glycidyl group-containing styrenic polymer (B) is more than 5 parts by mass, gelation may be caused by reaction with the thermoplastic polyester elastomer. Further, if the glycidyl group-containing styrenic polymer (B) is less than 0.5 parts by mass, the thickening effect is lowered, which is not preferable.

[C3-C40 organic carboxylic acid alkali metal salt (C)]
The C3-C40 organic carboxylic acid alkali metal salt (C) used in the present invention is an alkali metal salt of an aliphatic, alicyclic or aromatic carboxylic acid having 3 to 40 carbon atoms. As the alkali metal, sodium, potassium and lithium are preferable, and sodium is particularly preferable.
An aliphatic carboxylic acid is a compound in which a linear or branched aliphatic group has a carboxyl group, and an unsaturated group, an alicyclic group, an aromatic group or a hydroxyl group, a phosphate ester group is part of the bond. It may have other substituents such as. The aliphatic carboxylic acid is more preferably a compound in which a linear saturated aliphatic group is attached to a carboxyl group.

  Among the aliphatic carboxylic acids, propionic acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, mytilic acid, palmitic acid, margaric acid, stearic acid, oleic acid, linoleic acid, Montanic acid and the like are preferable, and among the alkali metal salts, sodium salt is soluble in polyester elastomer and has good crystal nucleation properties. Further, the thermoplastic polyester elastomer (A) and the glycidyl group-containing styrenic polymer (B It is preferable in terms of improving the stability of the melt viscosity.

The organic carboxylic acid of the organic carboxylic acid alkali metal salt (C) having 3 to 40 carbon atoms is an aliphatic carboxylic acid having 3 to 20 carbon atoms from the viewpoint of meltability and compatibility with the thermoplastic polyester elastomer (A). It is preferable.
Among these, an aliphatic carboxylic acid metal salt having less than 14 carbon atoms is preferable in that the crystallization rate can be improved with a small amount.

  The blending amount (content) of the C3-C40 organic carboxylic acid alkali metal salt (C) used in the present invention is (A) / (C) = mass ratio with respect to the thermoplastic polyester elastomer (A). 100 / 0.1-5. When the organic carboxylic acid alkali metal salt (C) is less than 0.1 part by mass, the effect of improving the crystallization rate is low, and the inner surface smoothness of the obtained molded product tends to be inferior. In addition, when the organic carboxylic acid alkali metal salt (C) is added in an amount exceeding 5 parts by mass, the thermoplastic polyester elastomer is significantly decomposed by the metal salt and the bending fatigue property is lowered, which is not preferable. The compounding amount of the organic carboxylic acid alkali metal salt (C) is preferably 0.2 to 3 parts by mass with respect to 100 parts by mass of the thermoplastic polyester elastomer (A). As for the compounding quantity of organic carboxylic-acid alkali metal salt, it is more preferable that it is 0.3-2 mass parts, and it is further more preferable that it is 0.5-1.5 mass parts.

[Inorganic crystal nucleating agent (D)]
The inorganic crystal nucleating agent (D) used in the present invention is not particularly limited as long as it is unmelted during melt processing and can become a crystal nucleus in the cooling process, but talc and calcium carbonate are particularly preferable. The particle size of the crystal nucleating agent (D) is preferably 0.1 to 10 μm, and more preferably 0.5 to 6 μm. When the particle diameter exceeds 10 μm, it acts as a foreign substance and may reduce the bending fatigue property. The compounding amount (content) of the crystal nucleating agent (D) is 0 to 3.0 parts by mass with respect to 100 parts by mass of the thermoplastic polyester elastomer (A). Exceeding 3.0 parts by mass is not preferable because bending fatigue properties are reduced.
In the present invention, the inorganic crystal nucleating agent (D) is an optional component, but by blending the inorganic crystal nucleating agent (D), there is an advantage that the appearance can be improved without impairing the melt viscosity. When mix | blending an inorganic crystal nucleating agent (D), it is preferable that it is 0.2-2.0 mass parts with respect to 100 mass parts of thermoplastic polyester elastomers (A).

  The polyester elastomer resin composition of the present invention is required to have a temperature-falling crystallization temperature (TC2) of 170 ° C. or higher, preferably 175 or higher, more preferably 180 ° C. or higher. In the present invention, the temperature-falling crystallization temperature (TC2) is obtained when a sample is melted in nitrogen at 250 ° C. for 2 minutes and then lowered to 50 ° C. at a temperature-falling rate of 20 ° C./min using a differential scanning calorimeter. Refers to the exothermic peak temperature of the temperature-falling crystallization obtained. When the temperature-falling crystallization temperature (TC2) is less than 170 ° C., the crystallization speed is too slow, so that the thickness unevenness of the molded product, the inner surface defect of the blow molded product due to melt fracture, etc. are likely to occur. The upper limit of the temperature-falling crystallization temperature (TC2) is not particularly limited, but is preferably 200 ° C. or lower.

  The polyester elastomer resin composition of the present invention needs to have a surface hardness of 35 or more in terms of D hardness (JIS K7215). Preferably it is 38 or more, More preferably, it is 40 or more. If the D hardness is less than 35, the effect of improving the moldability obtained is small, and the effect of improving the bending fatigue property of the molded product is also low. The upper limit of the surface hardness is not particularly limited, but is about 60 due to the characteristics of the thermoplastic polyester elastomer used.

The resin composition of the present invention preferably contains a general-purpose antioxidant such as an aromatic amine, a hindered phenol, a phosphorus, or a sulfur.
Specific examples of the aromatic amine antioxidant used in the resin composition of the present invention include phenylnaphthylamine, 4,4′-dimethoxydiphenylamine, 4,4′-bis (α, α-dimethylbenzyl) diphenylamine, and 4-isopropoxydiphenylamine and the like can be mentioned.

  Examples of the hindered phenol antioxidant include 2,4-dimethyl-6-t-butylphenol, 2,6-di-t-butylphenol, 2,6-di-t-butyl-p-cresol, and hydroxymethyl. -2,6-di-t-butylphenol, 2,6-di-t-α-dimethylamino-p-cresol, 2,5-di-t-butyl-4-ethylphenol, 4,4'-bis ( 2,6-di-tert-butylphenol), 2,2′-methylene-bis-4-methyl-6-tert-butylphenol, 2,2′-methylene-bis (4-ethyl-6-tert-butylphenol), 4,4′-methylene-bis (6-t-butyl-o-cresol), 4,4′-methylene-bis (2,6-di-t-butylphenol), 2,2′-methylene-bis (4 -Methyl-6-si Rohexylphenol), 4,4′-butylidene-bis (3-methyl-6-tert-butylphenol), 4,4′-thiobis (6-tert-butyl-3-methylphenol), bis (3-methyl-) 4-hydroxy-5-t-butylbenzyl) sulfide, 4,4′-thiobis (6-t-butyl-o-cresol), 2,2′-thiobis (4-methyl-6-t-butylphenol), 2 , 6-Bis (2′-hydroxy-3′-t-butyl-5′-methylbenzyl) -4-methylphenol, diethyl ester of 3,5-di-t-butyl-4-hydroxybenzenesulfonic acid, 2 , 2′-dihydroxy-3,3′-di (α-methylcyclohexyl) -5,5′-dimethyl-diphenylmethane, α-octadecyl-3 (3 ′, 5′-di-t-butyl-4 ′ Hydroxyphenyl) propionate, 6- (hydroxy-3,5-di-t-butylanilino) -2,4-bis-octyl-thio-1,3,5-triazine, hexamethylene glycol-bis [β- (3 5-di-t-butyl-4-hydroxyphenol) propionate], N, N′-hexamethylene-bis (3,5-di-t-butyl-4-hydroxyhydrocinnamic acid amide), 2,2-thio [Diethyl-bis-3 (3,5-di-t-butyl-4-hydroxyphenyl) propionate], dioctadecyl ester of 3,5-di-t-butyl-4-hydroxybenzenephosphonic acid, tetrakis [methylene- 3 (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2,4,6-tris (3 5-di-t-butyl-4-hydroxybenzyl) benzene, 1,1,3-tris (2-methyl-4-hydroxy-5-di-t-butylphenyl) butane, tris (3,5-di-) t-butyl-4-hydroxyphenyl) isocyanurate, tris [β- (3,5-di-t-butyl-4hydroxyphenyl) propionyl-oxyethyl] isocyanurate, and the like. Among these, those having a molecular weight of 500 or more such as tetrakis [methylene-3 (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane are particularly preferable because they do not easily volatilize in a high-temperature atmosphere.

  Examples of the phosphorus antioxidant include phosphorus-containing compounds such as phosphoric acid, phosphorous acid, hypophosphorous acid derivatives, phenylphosphonic acid, polyphosphonate, and diphosphite compounds. Specific examples include triphenyl phosphite, diphenyl decyl phosphite, phenyl diisodecyl phosphite, tri (nonylphenyl) phosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, bis (2 , 6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite.

  Examples of sulfur-based antioxidants include sulfur-containing compounds such as thioether-based, dithionate-based, mercaptobenzimidazole-based, thiocarbanilide-based, and thiodipropion ester-based compounds. Specific examples include dilauryl thiodipropionate, distearyl thiodipropionate, didodecyl thiodipropionate, ditetradecyl thiodipropionate, dioctadecyl thiodipropionate, pentaerythritol tetrakis (3-dodecyl thiopro Pionate), thiobis (N-phenyl-β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickel dibutyldithiocarbamate, nickel isopropylxanthate, tri Examples include lauryl trithiophosphite. In particular, a thioether-based antioxidant having a thioether structure can be suitably used because it receives oxygen from an oxidized substance and reduces it.

  The amount of each of the antioxidants is preferably 0.01 to 3 parts by mass, more preferably 0.05 to 2 parts by mass, and still more preferably 100 parts by mass of the thermoplastic polyester elastomer (A). 0.1 to 1 part by mass.

As a method for determining the composition and composition ratio of the polyester elastomer resin composition used in the present invention, it is also possible to calculate from a proton integration ratio of ¹ H-NMR measured by dissolving a sample in a solvent such as deuterated chloroform. is there.

  As a method for producing the thermoplastic polyester elastomer (A) in the present invention, a known method (Japanese Patent Laid-Open No. 9-59491, Japanese Patent Laid-Open No. 10-182954, Japanese Patent No. 4240467, etc.) can be employed. For example, the target thermoplastic polyester elastomer can be obtained by esterifying the dicarboxylic acid and the diol component at 150 to 250 ° C. and then polycondensing at 230 to 300 ° C. under reduced pressure. Alternatively, the target thermoplastic polyester elastomer is obtained by performing a transesterification reaction at 150 to 250 ° C. using a derivative such as dimethyl ester of the dicarboxylic acid and a diol component and then decondensing at 230 to 300 ° C. under reduced pressure. be able to.

  Furthermore, when weather resistance is required for the resin composition of the present invention, it is preferable to add an ultraviolet absorber and / or a hindered amine compound. For example, 2,2′-dihydroxy-4-methoxybenzophenone can be used as a benzophenone-based, benzotriazole-based, triazole-based, nickel-based, or salicyl-based light stabilizer that can be blended in the polyester-based thermoplastic elastomer used in the present invention. 2-hydroxy-4-n-octoxybenzophenone, pt-butylphenyl salicylate, 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, 2- ( 2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t-amyl-phenyl) benzotriazole, 2- [2′-hydroxy-3 ′, 5′-bis (α, α-dimethylbenzylphenyl) benzotriazole, 2- (2′-hydroxy-3) '-T-butyl-5'-methylphenyl) -5-chlorobenzazotriazole, 2- (2'-hydroxy-3', 5'-di-t-butylphenyl) -5-chlorobenzothiazole, 2 , 5-bis- [5′-t-butylbenzoxazolyl- (2)]-thiophene, bis (3,5-di-t-butyl-4-hydroxybenzyl phosphate monoethyl ester) nickel salt, 2- Ethoxy-5-t-butyl-2'-ethyl oxalic acid-bis-anilide 85-90% and 2-ethoxy-5-t-butyl-2'-ethyl-4'-t-butyl oxalic acid-bis A mixture of 10-15% anilide, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2-ethoxy-2′-ethyloxaza Rick acid bisanilide, 2- [2′-hydroxy-5′-methyl-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetrahydrophthalimido-methyl) phenyl] benzotriazole, bis ( 5-benzoyl-4-hydroxy-2-methoxyphenyl) methane, 2- (2′-hydroxy-5′-t-octylphenyl) benzotriazole, 2-hydroxy-4-i-octoxybenzophenone, 2-hydroxy- Examples thereof include light stabilizers such as 4-dodecyloxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, and phenyl salicylate. The addition amount is preferably 0.1% or more and 5% or less based on the mass of the resin composition.

  Various other additives can be blended in the resin composition of the present invention. As additives, resins, inorganic fillers, stabilizers, and anti-aging agents other than those of the present invention that are widely used as additives for thermoplastic elastomers may be added within a range that does not impair the characteristics of the present invention. it can.

Other additives include mold release agents, color pigments, inorganic and organic fillers, coupling agents, tackifiers, quenchers, stabilizers such as metal deactivators, flame retardants, etc. You can also
The resin composition of the present invention comprises a thermoplastic polyester elastomer (A), a glycidyl group-containing styrene polymer (B), an organic metal carboxylic acid alkali metal salt (C) having 3 to 40 carbon atoms, and an inorganic crystal nucleating agent (D). It is preferable to occupy 80% by mass or more in total (however, the component (D) may be 0). The total of (A), (B), (C), and (D) is more preferably 90% by mass or more, and further preferably 95% by mass or more.

  The method for producing the resin composition of the present invention includes thermoplastic polyester elastomer (A), glycidyl group-containing styrene polymer (B), C3-C40 organic carboxylic acid alkali metal salt (C), and other optional components. Is melt-kneaded using an ordinary thermoplastic resin mixer typified by a single-screw or biaxial screw-type melt kneader or a kneader-type heater, and then pelletized by a granulation step.

The polyester elastomer resin composition of the present invention is characterized in that the melt flow rate at 230 ° C. and a load of 2.16 kg is 0.1 to 3.0 g / 10 min. Thereby, it becomes a thing suitable for blow molding.
Further, the polyester elastomer resin composition of the present invention is characterized in that the number of breaks at 120 ° C. dematcher is 3 million times or more in the bending fatigue test described in the section of the following examples.

  In order to describe the present invention in more detail, examples are given below, but the present invention is not limited to the examples. In addition, each measured value described in the Example is measured by the following method.

Falling crystallization temperature (TC2), melting point:
Using a differential scanning calorimeter “DSC220 type” manufactured by Seiko Denshi Kogyo Co., Ltd., 5 mg of a sample to be measured is placed in an aluminum pan, sealed with a lid, melted in nitrogen at 250 ° C. for 2 minutes, and a temperature drop rate of 20 The exothermic peak temperature of the temperature drop crystallization obtained when the temperature was lowered to 50 ° C. at a rate of ° C./minute was defined as the temperature drop crystallization temperature (TC2). In the measurement sample, the temperature was increased from 50 ° C. to 250 ° C. at 20 ° C./min, and the endothermic peak due to melting was taken as the melting point from the obtained thermogram curve.

Reduced viscosity:
0.02 g of sufficiently dried polyester resin was dissolved in 10 ml of a mixed solvent of phenol / tetrachloroethane (mass ratio 6/4) and measured at 30 ° C. with an Ubellose viscometer.
Acid value:
A 0.2 g sample was precisely weighed, dissolved in 20 ml of chloroform, and titrated with 0.01 N potassium hydroxide (ethanol solution). Phenolphthalein was used as an indicator.
surface hardness:
The measurement was performed according to JIS K7215 (-1986). The test piece used was a stack of three injection-molded products (length 100 mm, width 100 mm, thickness 2 mm) produced at a cylinder temperature of 240 ° C. and a mold temperature of 50 ° C., measuring pressure 5000 g, type D indenter A durometer was used, and the value 5 seconds after the start of measurement was defined as D hardness.

The following were used as raw materials.
[Thermoplastic polyester elastomer (A)]
A1:
According to the method described in JP-A-9-59491, a thermoplastic polyester elastomer having a terephthalic acid / 1,4-butanediol / polyoxytetramethylene glycol (PTMG; number average molecular weight 2000) of 100/90/10 mol% ( A1) was produced.
This polyester elastomer (A1) had a melting point of 205 ° C., a reduced viscosity of 2.15 dl / g, an acid value of 35 eq / t, and a D hardness of 40.
A2:
According to the method described in JP-A-9-59491, a thermoplastic polyester elastomer having a terephthalic acid / 1,4-butanediol / polyoxytetramethylene glycol (PTMG; number average molecular weight 1500) of 100/88/12 mol% ( A2) was produced.
The polyester elastomer (A2) had a melting point of 197 ° C., a reduced viscosity of 1.86 dl / g, an acid value of 38 eq / t, and a D hardness of 46.
A3:
According to the method described in JP-A-9-59491, a thermoplastic polyester elastomer having a terephthalic acid / 1,4-butanediol / polyoxytetramethylene glycol (PTMG; number average molecular weight 2000) of 100/75/25 mol% ( A3) was produced.
The melting point of this polyester elastomer (A3) was 170 ° C., the reduced viscosity was 2.20 dl / g, the acid value was 31 eq / t, and the D hardness was 31.

[Glycidyl group-containing styrene polymer (B)]
B1:
Glycidyl group-containing styrene acrylic polymer ARUFON UG-4070 (manufactured by Toa Gosei Co., Ltd., Mw: 9700, epoxy value 1.4 meq / g)
B2:
Glycidyl group-containing styrene acrylic polymer ARUFON UG-4050 (manufactured by Toa Gosei Co., Ltd., Mw: 8500, epoxy value 0.67 meq / g)
[Other thickeners]
B3:
N-substituted triisocyanurate TEPIC-S (Nissan Chemical Co., Ltd.)
B4:
Carbodiimide compound Carbodilite LA-1 (Nisshinbo Co., Ltd.)

[Alkali metal salt of organic carboxylic acid (C)]
C1:
Sodium stearate (Nippon Yushi Co., Ltd., melting point 230 ° C.)
C2:
Sodium caprylate (CapNa manufactured by Nitto Kasei Kogyo Co., Ltd., melting point 220 ° C.)
[Inorganic crystal nucleating agent (D)]
D1:
Talc (KCM7500, Hayashi Kasei Co., Ltd., particle size 5.8 μm)

[Other additives]
Release agent:
Lycowax E (manufactured by Clariant)
Aromatic amine antioxidants:
Non-flex DCD (Ouchi Shinsei Chemical Co., Ltd.)
Phenolic antioxidants:
Irganox 1010 (BASF)
Phenolic antioxidants:
Irganox 1098 (manufactured by BASF)

Examples 1-8, Comparative Examples 1-9
Using a twin screw extruder, various additives were melt-kneaded at 240 ° C. in the ratios (mass ratio) shown in Table 1 with respect to 100 parts by mass of the thermoplastic polyester elastomer, and then pelletized. The following evaluation was performed using the pellets of the polyester elastomer resin composition. The results are shown in Table 1.

[Melt flow rate]
Based on the test method (Method A) described in JIS K7210, the melt flow rate (MFR: g / 10 min) at a measurement temperature of 230 ° C. and a load of 2160 g was measured. For the measurement, a composition having a moisture content of 0.1% by mass or less was used.

[Bending fatigue test]
Using a dematcher bending crack tester BE-102 (manufactured by Tester Sangyo Co., Ltd.), the following predetermined test pieces were repeatedly bent at a rate of 300 mm / min between the chucks of 75 mm and 19 mm under an atmosphere of 120 ° C. The test was carried out at a speed, and the bending fatigue resistance was evaluated by the number of times until breakage. As the test piece, an injection molded product (width 20 mm, length 100 mm, thickness 3.6 mm, hinge portion R2.4) produced at a cylinder temperature of 240 ° C. and a mold temperature of 50 ° C. was used.
The evaluation of the bending fatigue resistance is shown by the following criteria.
“◎” if the number of flexing times to break is 5 million times or more.
“○” if the number of flexures to break is less than 5 million times and 3 million times or more
“△” if the number of bends before breakage is less than 3 million times and 1 million times or more
“X” if the number of flexing times to break is less than 1 million

[Evaluation of blow moldability]
The cylinder temperature of a direct blow molding machine (single screw extruder: L / D = 25, full flight screw, screw diameter 65 mm) was set to 180 to 230 ° C. to produce a direct blow molding bottle. A parison-forming die lip was attached to the tip of the cylinder, and blow air was sealed in the mold to form a bottle. At this time, the parison holding state and the product dimensions were evaluated.
○: The drawdown is very small and the shape is maintained. △: The drawdown is large and the shape collapses, but it can be blown somehow. ×: The drawdown is large and the shape collapses and cannot be blown.

[Evaluation of gelled product]
The presence or absence of a gelled product of the bottle molded product obtained by the blow molding machine was visually observed.
○: No gelled product is observed.
Δ: A gelled product is slightly recognized.
X: A gelled product is noticeable.

[Evaluation of inner surface of molded product]
The inner surface smoothness of the bottle molded product obtained by the blow molding machine was visually evaluated.
○: The inner surface is smooth and no roughness is observed.
Δ: Roughness is recognized on the inner surface.
X: Roughness of the inner surface is noticeable.

  The polyester elastomer resin composition of the present invention is low in gelation and can provide a blow-molded product with a smooth appearance on the inner surface of the molded product. Since the decrease in the crystallization speed can be suppressed while having a high melt viscosity, a blow molded product having excellent molding processability at the time of blow molding and excellent in bending fatigue resistance under a high temperature environment can be obtained.

Claims (8)

  Bonded is a hard segment made of polyester composed of aromatic dicarboxylic acid and aliphatic and / or alicyclic glycol, and at least one soft segment selected from aliphatic polyether, aliphatic polyester and aliphatic polycarbonate The glycidyl group-containing styrene-based polymer (B) 0.5 to 5 parts by mass and the organic carboxylic acid alkali metal salt (C) 0 having 3 to 40 carbon atoms with respect to 100 parts by mass of the thermoplastic polyester elastomer (A) thus obtained. 0.1 to 5 parts by mass and (D) 0 to 3 parts by mass of an inorganic crystal nucleating agent, and the cooling crystallization temperature (TC2) is 170 ° C. or more and D hardness is 35 or more. Polyester elastomer resin composition for molding.   The thermoplastic polyester elastomer (A) is a copolymer mainly composed of terephthalic acid, 1,4-butanediol and polyoxytetramethylene glycol, and the polyoxytetramethylene glycol has a number average molecular weight of 500 to 500. The polyester elastomer resin composition for blow molding according to claim 1, wherein the copolymer amount is 4000 to 20 mol% with respect to all glycol components constituting the thermoplastic polyester elastomer (A).   The glycidyl group-containing styrene-based polymer (B) is a glycidyl group-containing styrene-acrylic polymer, and has a weight average molecular weight (Mw) of 1000 or more and an epoxy value of 0.5 meq / g or more. Polyester elastomer resin composition for blow molding.   The polyester elastomer for blow molding according to any one of claims 1 to 3, wherein the organic carboxylic acid of the alkali metal salt (C) having 3 to 40 carbon atoms is an aliphatic carboxylic acid having 3 to 20 carbon atoms. Resin composition.   The polyester elastomer resin composition for blow molding according to any one of claims 1 to 4, wherein the inorganic crystal nucleating agent (D) is talc.   The polyester elastomer resin composition for blow molding according to any one of claims 1 to 5, wherein the melt flow rate at 230 ° C and a load of 2.16 kg of the polyester elastomer resin composition is 0.1 to 3.0 g / 10 min. .   The polyester elastomer resin composition for blow molding according to any one of claims 1 to 6, wherein the polyester elastomer resin composition has a breakage of 120 ° C dematcher of 3 million times or more.   The thermoplastic polyester elastomer (A) is blended with a glycidyl group-containing styrenic polymer (B) as a thickener, and a nucleating agent and a C3-C40 organic carboxylic acid alkali metal salt (C) as a reaction catalyst. A method for producing a polyester elastomer resin composition for blow molding, which comprises blending.